[
https://issues.apache.org/jira/browse/FLINK-23208?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Jiayi Liao updated FLINK-23208:
-------------------------------
Priority: Critical (was: Major)
> Late processing timers need to wait 1ms at least to be fired
> ------------------------------------------------------------
>
> Key: FLINK-23208
> URL: https://issues.apache.org/jira/browse/FLINK-23208
> Project: Flink
> Issue Type: Bug
> Components: Runtime / Task
> Affects Versions: 1.11.0
> Reporter: Jiayi Liao
> Priority: Critical
>
> The problem is from the codes below:
> ```
> public static long getProcessingTimeDelay(long processingTimestamp, long
> currentTimestamp) {
> // delay the firing of the timer by 1 ms to align the semantics with
> watermark. A watermark
> // T says we won't see elements in the future with a timestamp smaller
> or equal to T.
> // With processing time, we therefore need to delay firing the timer by
> one ms.
> return Math.max(processingTimestamp - currentTimestamp, 0) + 1;
> }
> ```
> Assuming a Flink job creates 1 timer per millionseconds, and is able to
> consume 1 timer/ms. Here is what will happen:
> * Timestmap1(1st ms): timer1 is registered and will be triggered on
> Timestamp2.
> * Timestamp2(2nd ms): timer2 is registered and timer1 is triggered
> * Timestamp3(3rd ms): timer3 is registered and timer1 is consumed, after
> this, {{InternalTimerServiceImpl}} registers next timer, which is timer2, and
> timer2 will be triggered on Timestamp4(wait 1ms at least)
> * Timestamp4(4th ms): timer4 is registered and timer2 is triggered
> * Timestamp5(5th ms): timer5 is registered and timer2 is consumed, after
> this, {{InternalTimerServiceImpl}} registers next timer, which is timer3, and
> timer3 will be triggered on Timestamp6(wait 1ms at least)
> As we can see here, the ability of the Flink job is consuming 1 timer/ms, but
> it's actually able to consume 0.5 timer/ms.
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
